Arguments

cellRange

a string specifying the cell range. For example a
standard area ref (e.g. "B1:D8"). May be a single cell ref (e.g. "B5")
in which case the result is a 1 x 1 cell range. May also be a whole
row range (e.g. "3:5"), or a whole column range (e.g. "C:F")

colIndex

a numeric vector specifiying the columns you want to
auto size.

colSplit

a numeric value for the column to split.

colWidth

a numeric value to specify the width of the column.
The units are in 1/256ths of a character width.